Method of sensitizing cylinders



Patented Sept. 1, 1925.

UNITED STATES PATENT oFFicE.

FRED M. CARROLL, OF ENDICOTT, NEW YORK, .AS-SIGNOR TO THE TABULATING MA- CHINE COMPANY, OFJENDICOTT, NEW YORK, .A CORPORATION OF NEW JERSEY.

Application led August 21, 1924.` Serial No; 788,290:

To all whom t may concern:

Be it known that I, FRED M. CARROLL, a'

citizen of the United States of America, residing at Endicott, in ,the county of Broome and State of New York, have invented certo receive an image of data which is to bev reproduced thereon by etching processes.

The present invention is particularly directed/to an improved method of sensitizingthe cylinders to the general end that the coating of sensitizing material may be JObviously ifthis distributed in a uniform manner upon the cylinder periphery.

In the drawings:

Fig. 1 is a view showing the first step of the method which comprises the application of the material to the vcylinder and the distribution of the same thereon.

Fig. 2 shows the second step in the method. In this step Yheat is applied to the cylinder in a novel inanner to cause` the congealing hardening and \dr ing of the material in a uniform distributionupon the cylinder.

In more detail, 10 represents a cylinder of copper, brass or like material. This cylinder is ground and polished to exact size and then applied to a mandrel 11' with its axis horizontal. After the cylinder is in place upon the mandrel, the cylinder is rotated or spun by any suitable means such as the electric motor 12. The operator then applies a small amount, usually eight or ten drops, lof the sensitizing emulsion to the I l cylinder while the latter is rotating. This emulsion may be of various consistency, and

may include albumen or collodion, to-

i gether with any suitable reagent which is acted upon by light. Application of the emulsion to the cylinder may be conveniently effected by sush means as the dropper-13.

The rotation of the cylinder is continued and the emulsion is spread b avsuitable paddle. The emulsion is kept om flowing downwardly to a low point on the periphery of the cylinder by the forces which are set up by the rotation of the cylinder.

The cylinder rotation is then stopped, the cylinder removed and placed one kend up (i. e. with its axis vertical) upon a suitable support or table 14.

The operator then applies a heated iron block 15 to the upper end of the cylinder as shown in Fig. 2. The subsequent effect may be explained as follows: When the cylinderis placed end up upon the table the emulsion starts to run down the periphery of the cylinder lengthwise thereof and thus evens out any irregularities in the emulsion that may have ybeen formed therein during the rotation or s inning of the cylinder.

ibw of the emulsion were unimpeded the coating would be very thin at the top and thicker at points lower down.

T11-isis undesirable. The transfer of heat from the heated block to the cylinder proceeds and the heat thus imparted causes the emulsion to congeal upon the periphery of" 1heat to one end of `the cylinder to congeal the emulsion after the latter has flowed slightly downwardly upon the periphery of the cylinder.

2.- The method of coating cylinders with a sensitizino' emulsion, which comprises first rotating the cylinder about a horizontal axis, then applying and spreading emulsion thereto and thereon while the cylinder is rotating and thereby maintaining the distribution of emulsion about the periphery of the cylinder, then disposing the cylinder with its axis vertical'to causewa slight downward How of the emulsion and thereafter" congealing the emulsion by aplyng heat to vthe cylinder.Y 3. The metho of coatingl a cylinder with a sensitizin emulsion whlch comprises rotating a cy inder with its axis horizontal, 5 then applying the sensitized emulsion thereto an distrlbutng the same thereon by spreading aided by spinning of the cylin der, thereafter placing the cylinder with its axis in a vertical position, and euhm .upgr end of said cylinder.

testimony whereof I hereto ax my signature.

FRED M CARROLL. 

